At present, as environmental countermeasures, secondary batteries such as high-capacity lithium-ion batteries have attracted a lot of attention as power supplies for electric vehicles, power-driven engines, and electronic devices. When a lithium-ion battery is taken as an example, an electrode in which a positive electrode active material is applied to a band-shaped positive electrode current collector formed from aluminum foil is used as its positive electrode, and an electrode in which a negative electrode active material is applied to a band-shaped negative electrode current collector formed from copper foil is used as its negative electrode. A battery element produced by winding the positive electrode current collector and the negative electrode current collector via a separator into a cylinder shape is stored into a cylindrical battery can, or a battery element obtained by winding the positive electrode current collector and the negative electrode current collector via a separator into a bobbin shape is formed into a flat shape and stored into a square-shaped battery can or bag. An electrolyte is injected thereinto and the can or bag is closed to produce a lithium-ion battery.
Electrode applied portions that are to be electrodes such as the positive and negative electrodes are formed on a long and wide original fabric into rectangular shapes at equal intervals by screen printing. Thus, when the original fabric is removed from the screen, spiny small projections occur on boundary portions of the viscous applied portions. When the electrode applied portions are solidified to form electrodes and then the original fabric is slit with a predetermined width dimension to form narrow band-shaped current collectors and they are wound via a separator as described above, the spiny projections are broken and remain as foreign matter, or the spiny projections that are not broken break through the separator to cause short circuit between the positive and negative electrodes. Thus, the temperature of the battery abnormally increases, and fire infrequently occurs in terrible cases.
Thus, in order to prevent such short circuit between electrodes, an insulating film is attached so as to cover the overall width of the boundary portion between an electrode and a non-applied portion. In such a case, in order to accurately attach the insulating film to the boundary portion in a tensioned manner, it is necessary to accurately pitch-feed the original fabric. In a conventional original fabric pitch feed mechanism, the original fabric is sandwiched between nip rollers from above and below, and the nip rollers are rotated by a predetermined angle to pitch-feed the original fabric. However, the portions of electrodes that are formed on the front and back of the original fabric are thick as compared to electrode non-formed portions, and due to the steps, slippage occurs at the electrode non-formed portions. Thus, accurate pitch feed cannot be performed, and the feed speed is not sufficient.
Such a problem is also seen in a battery manufacturing site, and, for example, countermeasure using an elevating roller as disclosed in Patent Literature 1 is also proposed as one of solutions to the problem. However, when an electrode sheet is fed solely with the elevating roller, high-speed rough feed and subsequent low-speed accurate feed have to be combined since the electrode sheet is not assuredly fixed. Thus, a transfer method is complicated, and the efficiency is poor in terms of work efficiency since the two types of feeds have to be combined.